Senior Front-End Developer

We are looking for a Senior Front-End Developer to take ownership of real-time rendering, networking and performance within a multiplayer browser-based game environment.

Role is based in Warsaw, Poland (relocation support provided).

Responsibilities:

• Maintain and optimize the core game loop to ensure consistent 60 FPS rendering under varying system loads.
• Design and implement two-way socket communication, incorporating interpolation, reconciliation, and fault-tolerant architecture.
• Build a modular UI and animation framework that supports dynamic layouts, multilingual bidirectional text, and multiple visual styles.
• Create custom profiling and asset-loading tools to monitor memory usage, manage resource lifecycles, and evaluate frame performance.
• Independently integrate and extend engine modules, researching and adopting new APIs or third-party libraries when necessary.
• Optimize for mobile performance and cross-device consistency, while actively preventing memory leaks.

Requirements:

• Strong experience with JavaScript/TypeScript, game development fundamentals, and real-time multiplayer architecture.
• Hands-on experience with WebGL or Canvas-based engines such as Cocos, PixiJS, or Phaser; familiarity with the Spine SDK.
• Proven contribution to the full development cycle of released 2D browser-based multiplayer games.
• Deep understanding of GPU-accelerated rendering pipelines (WebGL/Canvas) and shader usage.
• Expertise in designing real-time network systems, including latency handling, message sequencing, and retry mechanisms.
• Strong grasp of state management and event-driven design in interactive client-side applications.
• Advanced knowledge of memory management, garbage collection, and performance profiling.
• Ability to work autonomously, including researching, prototyping, and implementing new technologies or engine extensions.
• Languages proficiency: at least Intermediate level of English, Upper-intermediate level of Ukrainian and Russian. 
  

What’s in it for you:

• Competitive compensation package.
• Relocation support.
• Paid vacation and sick leave.
• Opportunities for professional growth and learning.
• Supportive environment with autonomy and ownership.
• Involvement in technically challenging, fast-paced game development projects.